Automatic jump rope apparatus



Aug. 30, 1960 B. L. WOLFSON AUTOMATIC JUMP ROPE APPARATUS Filed Oct. 30, 1959 IN VENTOR WOLFSO/V 5mm L.

23 BY Km) ATTORNEYS ite tates Patent 2,950,779 Patented Aug. 30, 1960 AUTOMATIC JUMP ROPE APPARATUS Byron L. Wolfson, 5617 Hollywood Blvd, Hollywood, Calif.

rna Get. 30, 1959, Ser. No. 849,948

Claims. (Cl. 185-67) The present invention relates to an apparatus for rotating one end of a jump rope and, more particularly, to a clutch mechanism to be employed with an automatic jump rope mechanism as disclosed in co-pending US. patent application No. 736,746, filed by the present inventor on May- 21, 1958, now Patent No. 2,911,063 granted Nov. 3, 1959. In the apparatus disclosed in the aforesaid patent application, an elongated shaft is rotatably supported in a generally horizontal position by two bearing structures attached to a supporting frame. Disposed on one end of the shaft, externally of the frame, is a weighted arm which is generally perpendicular to the shaft; and a rope to be rotated is attached to the end of the arm. The arm is rotated by two spiral springs disposed about the shaft with each having one of its ends secured to the shaft and the other end secured to the frame. The convolutions of the spring are oppositely directed so that, when one spring is wound, the other is unwound. A crank is disposed at an end of a shaft remote from the aforesaid arm; and, initially, the crank is rotated so that one of the spiral springs is tightly wound and the other is unwound. Upon releasing the handle, the shaft rotates in one direction for a predetermined number of turns unwinding the wound spring and winding the unwound spring. When the force on the spring that is being wound equals the force of momentum of the rotating arm, the rotation of the arm, in its first direction, is stopped; and, thereafter, the spring that is now wound causes the arm to rotate in a direction opposite to its original direction of rotation.

In the aforesaid application, it is stated that the arm rotates a number of turns in one direction, then rotates in the opposite direction until the first spring is rewound, and then rotates back in the original direction, etc., so that a number of oscillatory rotations may thus be implemented. The system may be designed so that a maximum number of rotations are imparted in the original direction of rotation; and the arm is then rotated back a considerable number of turns in the opposite direction but, thereafter, not too many rotations or oscillations occur. Although the system described in the aforesaid application permits a large number of rotations of the rope to be effected and provides a completely satisfactory and operable device, it is an object of the present invention to increase the total number of rotations which may be provided by the automatic jump rope apparatus. It is apparent that, in any system where one spring is being wound while the other spring is being unwound, the spring being wound exerts a backward torque on the rotating member and eventually prevents further rotation and initiates rotation in the opposite direction. Thus, although the utilization of the two oppositely Wound springs increases the number of rotations which are possible with a single spring, the force of the springs are still opposed during a part of the operating cycle and tend to nullify some of the advantage which might otherwise be obtained. It is an object of the present invention to increase the total number of rotations which may be imparted to a rotary body in response to the torsion forces developed by two oppositely wound springs operating on the rotating mechanism.

It is another object of the present invention to provide a clutch device which permits the force of one of two springs operating in opposite directions upon a rotating body to be eliminated during rotation imparted to the body by the other of the springs.

In accordance with the present invention, the generally horizontal shaft, to which the springs of the aforesaid patent are attached, comprises two shafts connected together by a selectively engageable clutch. Further, the two oppositely wound springs are of different force characteristics; and a li hter or softer spring is connected. to the part of the horizontal shaft connected to the arm to which the jump rope is tied, and a heavier of the two springs is attached to the part of the shaft connected to the crank. The clutch selectively couples the two sections of the shaft, one to the other, and, initially, the apparatus is rotated so as to tension the heavier of the two springs. Tensioning of the heavier of the'two springs causes the clutch to couple the two sections of the shaft together so that, upon releasing the handle, the entire shaft and the arm are rotated as a single unit. During winding of the heavier spring, the lighter spring would normally be unwound past its neutral or no force position if it were attached directly to the horizontal shaft. Assuming that there is a position of the horizontal shaft where both springs are unwound then winding of one spring unwinds the other andwhen the wound spring is released, no tensioning or winding of the unwound spring can occur until it is returned to its neutral position. In this way, only a part of the force stored in the heavy spring is imparted to the lighter spring. In order to overcome this problem, the lighter spring is connected to the shaft through a conventional one way clutch so that during winding of the heavier spring, the lighter spring is disconnected from the shaft and is connected only during unwinding of the heavier spring.

During unwinding of the heavier spring, the lighter spring is wound; and, when the heavy spring becomes unwound, the two halves of the shaft are decoupled from one another and the lighter spring causes the arm to reverse its direction of rotation. During this interval, since the part of the shaft to which the heavier spring is connected is decoupled from the other section of the shaft, the lighter spring rotates free of the back torsional force that would otherwise be exerted by the heavier spring and also free of the inertia and friction of the nowdecoupled pawl of the shaft. In consequence, the total number of rotations imparted to the apparatus is considerably increased over that available in the apparatus of the aforesaid application.

The reason for utilizing a heavier and lighter spring combination is that the lighter spring reduces the number of rotations which may be effected by the heavier spring by only a relatively small percentage; and, of course, after decoupling, the heavier spring has no effect upon the number of rotations which may be imparted to the arm by the lighter spring.

It is, therefore, another object of the present invention to provide an automatic jump rope apparatus employing two oppositely wound springs for imparting oscillatory motion to a rotatable arm in which a clutch mechanism is employed for selectively coupling two sections of a horizontal, rotatable shaft to one another during rotations effected by the heavier spring and for decoupling the two sections of the shaft from one another during rotations imparted by the lighter spring.

It is yet another object of the present invention to provide an automatic jump rope apparatus employing two oppositely wound springs for imparting oscillatory motion to a rotatable arm in which a first spring is decoupled from the shaft during winding of a second spring and the second spring is decoupled from the shaft during unwindingof the first spring. Y

It isfst'ill another object of the present invention to provide an automatic. jump rope apparatusv employing oppositely wound. heavier and lighter soil springs. adapted to be coupled to a shaft for iinpartingos'cillatory motion to. the shaft in which the lighter spring: is decoupled from the shaftsduring winding ofthe heavier spring and the heavier spring and a part of. the shaft is decoupled from the rewinder of the shaft during unwinding of the lighter spring. a

, It is yet another object of the present invention to provide a novel clutch mechanism. for interconnecting the two axially-aligned, rotatable shafts;

It is still another object of the present invention to provide a clutch assembly for selectively coupling two axiallyali'gned shafts, one to another, under the control of the tension in aspring employed for rotating the shaft.

Q The above and still further objects, features and advantages ofthe-present invention will become apparent upon consideration of the following detailed description of one specific embodiment thereof, especially when taken in conjunction with the accompanying drawings, wherein:

Figure 1 is a perspective view of an automatic jump rope mechanism to'which the present invention may be applied; 7

. Figure 2 is a cross sectional view 'of the horizontal shaft and clutch assembly employed in the assembly of the present invention; a V a Figure 3 is a cross sectional view taken at right angles to Figure 2.

Referring specifically to Figure 1 of the accompanying drawing, which illustrates'the automatic jump rope mechanism of the aforesaid application, 'there is provided a frame, generally designated by the reference numeral 1, comprising a first hollow, inverted U-shaped member 3, spaced from and disposed parallel to the first. The U- shaped frames 2 and 3' are interconnected by a bar 4 which is secured to and disposed perpendicularly of the frame members 2 and 3. Disposed within each of the hollow legs of the U-shaped member 2 is a tubular leg 6 which ;is vertically adjustable with respect to the member 2 and which may be secured in any'given vertical position-by means of thumb screw 7. Similarly, the frame 3 is pro- 7 vided with two legs 8 which may slide internally'of the hollow side legs of the U-shaped frame 3 and are secured in a'given position by means of thumb screw'9.

Disposed between the legs of the U-shaped member 2 is a hub 11 which is supported between the legs of the member 2 by means of a plurality of radially extending spokes 12. Similarly, a hub 13 is disposed between the legs of the U-shaped frame 3, and supported therebetween by a plurality of radially extending spokes'or bars 14. The hubs 11 and 13 are axially aligned and are adapted to support ashaft 16 of a crank generally designated by the reference numeral 17 and having a crank handle 18. The crank handle 18 is disposed outwardly of the frame member 3, while the crank shaft 16 extends through the hub 11 and forwardly'of the frame member 2. .An ad'- justable collar19'is disposed about the crank shaft '16 and is normally maintained in engagement with the hub 17 so as to prevent end'motion of thecrank shaftlfi.

The spiral springs 22 and 23 are disposed'about the shaft 16 and have one end secured to the shaft 16. The other end of the spring 23, which is designated by the reference numeral 26, is secured to a U-shaped retainer 27 disposed on the shaft 4, while the corresponding end a of the spiral spring 22 is also secured to a U-shaped mem ber. disposed on a surface of the bar 4. The ends of the springs.22 and 23' are formed generally into loops 29 so that they curve about the U-shaped retaining members and are thereby secured thereto. The convolutionsof the springs22 and 23are oppositely directed sothatt y tend to rotate the shaft 16 in opposite directions. Winding of one of the springs and unwinding of the other is effected by rotating the crank handle 18 in a given direction. When the handle is released, the wound spring unwinds while the unwound spring winds until a balance of forces is effected, at which time the spring which was originally unwound winds and vice versa At this time, the direction of rotation of the shaft 16 is reversed; and this process continues until all ofthe initial energy stored in the originally wound. springs is dissipated.

Secured to the endof the shaft 16, remote from the crank handle 18, is a hollow arm 31 which extends substantially at right angles to the; shaft 16. The hollow arm 31 is adapted to support a rod 32which' is disposed within thehollow arm 31 and isslidable with respect thereto. The arm 32 is provided with a weight 34 and terminates at its end in a loop 36 to which a jump rope 37 may be tied- The purpose of the weighting of the arm 34 is twofold. In a first instance,.it.serves to increase the moment of inertia of the transverse arm to which the rope 37 is attached; and, therefore, by adjusting the total length of the arm comprising the members 31 and 32, the rate at which the rope is rotated may be controlled. The other purpose for the weight 34 is to reduce the angular velocity of the rope on upward movement of the arms 31 and 32 to thereby simulate the motion of a jump rope propelled by human means.

Referring now specifically to Figure '2 of the accompanying drawings, there is illustrated an arrangement in accordance with the present invention for selectively coupling and decoupling two axially aligned sections of the shaft 16 from one another. In accordance with the present invention, the shaft 16 comprises a large external shaft 38 and a smaller orinterior shaft 39 axially aligned with one another. The enlarged shaft 38 is provided with an axial recess 41 in an end facing the arm 31, the recess 41 being of an internal diameter such as to receive, relatively snugly, an end of the shaft- 39 remote from the arm 31. The shaft 39 is supported by the collar 11 which is suspended from the frame 2 by means of the arms 12. The spring 22 has its inner end secured to an outer member of slip ring 35 of a one way clutch 40 secured to the shaft 39; The clutch 40 is of conventional design and maybe of the type described and illustrated in US. Patent No. 2,069,558. The outer end of spring 22 is secured to'the bar'4 while the spring 23, although coupled to and acting upon the shaft 38 is notdirectly connected thereto. Specifically, the spring 23 has an outer endsecured to the U-shaped member 27 of the bar 4, as illustrated in Figure 1, and has its inner end, designated by reference numeral 42, secured to a head 43 of a reciprocatable plunger 44.

The plunger 44- is disposed in a transverse cylindrical aperture 46 in the shaft 38 which is axially, though not always radially, aligned with a generally parabolic-shaped, transverse recess 47 in the shaft 39-. As indicated in the aforesaid patent and in the description relating to Figure l, the shaft 4 is prevented from moving horizontally by appropriate stop members and the same is true in the present invention so that the shafts 38 and 39 cannot move relative to one, another; and, therefore, the aperture 46 and recess 47 remained axially aligned. The plunger 44, when in the position illustrated in'Figure 2, couples the shafts 38' and 39, one to the other, so that rotation imparted to one is also imparted to the other. .The plunger44 is maintained in the aperture 46 by a cover plate 48 having a central aperture 49'fo'rmed therein through which the plunger 44 passes. The cap 48 .serves to prevent the plunger 44 from being withdrawn completely from the recess 46 and also serves to maintain the plunger latched in an upward position. In order to effect latching of the plunger, there is provided a'cir- 'cumferential recess. 51 and" a circumferential outward extension: on lip 52 on. the body of the plunger 44. To latchthe plunger 44 inan upward position, as illustrated inFigure 3, the plunger'israised until the lip-52 is drawn through the recess 49 which is smaller than the lip 52. The material from which the plate 48 is fabricated is flexible, and therefore, permits withdrawal of the lip through the aperture in spite of the fact that the lip is of greater diameter. It is apparent that, once the lip 52 is above the plate 49, an external force must be applied to the plunger to move the lip 52' past the plate 48. The plate 48 may take the form of a speed nut so that the force required to move the lip 52 through the aperture 49 in the declutching direction is less than that required to move it in the opposite direction.

In the operation of the apparatus, the crank 17 is rotated initially so as to completely wind the spring 23 which is stronger or heavier than the spring 22. Since the plunger 44 is secured to an end 42 of the spring 23, tensioning of the spring by winding causes the convolutions to contract and forces the plunger 44 downwardly towards the recess 47. When the aperture 46 is aligned with the aperture 47, the plunger 44 is forced into the recess 47; and the shafts 38 and 39 are connected to one another. However, the spring 22 is decoupled from the shaft 39 by the clutch 40 and is not affected by rotation of the shaft. When the spring 23 has been completely wound, the handle is released; and the shaft 16, or specifically, the shafts 38 and 39, are caused to rotate counterclockwise as illustrated in Figure 1. During the period of unwinding of the spring 23, the spring 22 is coupled to shaft 39 by clutch 46 and is wound but since it is a smaller or lighter spring than spring 23, it does not seriously affect the number of revolutions which may be imparted to the shaft by the spring 23.

The springs 22 and 23 are arranged such that, when the spring 22 is wound by the operation of the apparatus, the spring 23 is under compression having previously passed through its neutral force portion. Under these conditions, the spring 23 pulls upwardly on the plunger 44 with sufficient force to withdraw the circumferential projection 52 upwardly through the aperture 49 in the plate 48 so that the plunger becomes latched in an up ward position in which it is completely withdrawn from the recess in the shaft 49, this condition being illustrated in Figure 3 of the accompanying drawings. In conse quence, the shaft 38 is decoupled from the shaft 39, and rotation is imparted to shaft 39 by means of the spring 22 which at this time is completely wound. The spring 22 rotates the arm 39 until its force is substantially completely expended; and it will be noted that, during the interval that the spring 22 is unwinding, the spring 23 is ineffective in the system since it is decoupled from the shaft 39. Further, since the plate 48 and projection 52 cooperate to latch the plunger 44 in its upward position, the shaft 33 is free to be rotated by the spring 22 until the spring has assumed a normal or central position but the force exerted on the plunger 44 during this unwinding procedure is insufficient to cause the plunger to free itself from the plate 48; and thus, the plunger remains in its upward or decoupling position. The only way that the plunger can be forced downward into the recess 47 in the shaft 39 is for the spring 23 to be tightly wound and this occurs only when the mechanism is cranked by the operator.

While I have described and illustrated one specific embodiment of my invention, it will be clear that variations of the details of construction which are specifically illustrated and described may be resorted to without departing from the true spirit and scope of the invention as defined in the appended claims.

What I claim is:

l. A mechanism for rotating a length of flexible material comprising a first shaft, a second shaft axially aligned with said first shaft, spaced bearings for rotatably supporting said shafts in generally horizontal positions, a frame for supporting said bearings, a heavy spiral spring disposed about said first shaft and having its inner end 6 coupled thereto, a light spiral spring disposed about said second shaft and having its inner end coupled thereto, said spring having their convolutions directed in opposite directions and having their outer ends secured to said frame, a handle for rotating said first shaft to wind said heavy spring, a clutch means for selectively coupling said shafts one to another, said clutch means coupling said shafts substantially only during rotation of said second shaft in a direction determined by said heavy spring.

2. A mechanism for rotating a length of flexible material comprising a first shaft, a second shaft axially aligned with said first shaft, spaced bearings for rotatably supporting said shafts in generally horizontal positions, a frame for supporting said bearings, a heavy spiral spring disposed about said first shaft and having its inner end coupled thereto, a light spiral spring disposed about said second shaft and having its inner end coupled thereto, said springs having their convolutions directed in opposite directions and having their outer ends secured to said frame, a handle for rotating said first shaft to wind said heavy spring, a selectively engageable clutch for coupling said shafts, one to the other, and means for engaging said clutch when said heavy spring obtains a predetermined tension on winding and for disengaging said clutch when said heavy spring obtains a predetermined compression on unwinding.

3. A mechanism for rotating a length of flexible material comprising a first shaft having an axially extending cylindrical recess in one end, a cylindrical shaft having one end received in said recess in said first shaft, spaced bearings for rotatably supporting said shafts in generally horizontal positions, a frame for supporting said bearings, a heavy spiral spring disposed about said first shaft and having its inner end coupled thereto, a light spiral spring disposed about said second shaft and having its inner end coupled thereto, said springs having their convolutions directed in opposite directions and having their outer ends secured to said frame, a handle for rotating said first shaft to wind said heavy spring, a. clutch means for selectively coupling said shafts one to another, said clutch means coupling said shafts one to the other substantially only during rotation of said second shaft in a direction determined by said heavy spring.

4. The combination according to claim 3 further comprising a one way clutch connected to said second shaft, said light spring having its inner end connected to said one way clutch, said one way clutch being arranged to connect said light spring to said second shaft during rotation of said second shaft by said heavy spring.

5. A mechanism for rotating a length of flexible material comprising a first shaft having an axially extending cylindrical recess in one end, a cylindrical shaft having one end received in said recess in said first shaft, spacing bearings for rotatably supporting said shafts in generally horizontal positions, a frame for supporting said bearings, a heavy spiral spring disposed about said first shaft and having its inner end coupled thereto, a light spiral spring disposed about said second shaft and having its inner end coupled thereto, said springs having their convolutions directed in opposite directions and having their outer ends secured to said frame, a handle for rotating said first shaft to wind said heavy spring, a selectively engageable clutch for coupling said shafts one to the other and means for engaging said clutch when said heavy spring obtains a predetermined tension on winding and for disengaging said clutch when said heavy spring obtains a predetermined compression on unwindmg.

6. The combination according to claim 4 wherein said clutch comprises a plunger, a transverse aperture in said first shaft for slidably receiving said plunger, a recess in said second shaft aligned with said aperture in said first shaft, said heavy spring having said inner end secured to said plunger.

7. The combination according to claim 5 further com- 7 Jprising means for latching said plimger in a position where his withdrawn from said recess in said second shaft. r t .8. The lcombinationaccordingto claim 5 further comprising a'one way clutch connected to said second shaft,

said light spring having its inner endrconnected to said one way clutch, said .one way clutch being arranged to .connect'said light spring to said second shaft during rota- Vtion of said secondrshaft by said heavy spring.

aligned with said aperture, la ip'lunger vfor coupling said members, said plunger'slidably received in said aperture and said recess, a spiral spring disposed about said first member and having one endseeured to .said plunger, means for retaining'said plunger in ,said aperture and means for tensioning said spring, :atwill, to 'bias .said plunger into, said radial recessi a 10. The combination according toclaim 9 further comprising means for temporarily latching said plunger in a w g position in which itis withdrawn from said recess.

References-Cited indie-file of this patent UNITED STATES PATENTS Wolfson Nov. 3, 1959 m a. Air 

